Surface roughness parameter measurement method based on three-dimensional contour line

The invention discloses a surface roughness parameter measurement method based on a three-dimensional contour line, which comprises the following steps of: firstly, acquiring infrared images of four polarization angles on the surface of a roughness comparison sample block, secondly, calculating polarization parameters of infrared radiation by solving a Stokes vector, establishing a relationship between target infrared radiation polarization characteristics and a surface normal vector, and finally, measuring the surface roughness parameter of the roughness comparison sample block according to the relationship between the target infrared radiation polarization characteristics and the surface normal vector. Then analyzing the three-dimensional form of the target surface through a global integration method; and finally, extracting ten profile contour lines from the three-dimensional surface and calculating roughness Ra, Rq and Rz parameters. The method is not influenced by the rare characteristic of the feature p